The manuscripts, which were written on fragile birch bark, provide an important insight into the development of Buddhist literature and help fill the gaps in some areas of Buddhist history.

Buddhism was traditionally a spoken tradition and until now, little has been known about how it developed from the spoken to the written word.

While Buddhism flourished throughout Asia, it disappeared from India, Central Asia and the Indonesian archipelago, taking with it many literary traditions.

"When we first learnt about these manuscripts we looked at the scripts and the language and made a rough estimate of their approximate age," says Dr Mark Allon, from the University of Sydney, an Australian researcher who is translating the text.

The scientists used the process of accelerator mass spectrometry to radiocarbon date the bark on which the manuscipts were written.

This process counts the rare carbon-14 isotopes in a sample and uses this to calculate the sample's approximate age based on the radioactive decay over time.

Two manuscripts from the Senior collection, which is named after the scrolls' British owner, date to between 130 and 250AD

And three manuscripts from the Schøyen text, named after the scrolls' Norwegian owner, date to between the 1st and 5th century AD.

Allon says the Senior collection dating is particularly important because it makes a major contribution to Indian Buddhism chronology.

"One of the manuscripts we studied was found in a pot with an inscription on it indicating that it was donated in the year 12. While it didn't say what era that was, the characteristics of the inscription tell us that it must refer to the Kanishka era."

Kanishka was a very important king in northern India in about the 1st or 2nd century AD, but the dates he lived and ruled have been debated for a century or more.

"What the carbon dates told us was that the earlier date favoured by some scholars, namely 78AD, is no longer tenable because the carbon dates tell us that the manuscripts actually dated from 130AD to 250AD."

The manuscripts are believed to have originated from Afghanistan and are among many archaeological artefacts that were sold on the international market in times of war.